1. Technical Field
The present invention relates to an electro-optical device provided with an electro-optical panel having electro-optical elements, such as light-emitting elements or light valve elements, therein, to an image printing apparatus using an electro-optical device, and to a method of manufacturing an electro-optical device.
2. Related Art
There has been developed a technique for using an electro-luminescent element (hereinafter, referred to as ‘EL elements’) array to write an electrostatic latent image on an image carrier (for example, a photosensitive drum) of an image printing apparatus using an electrophotography method. In this technique, generally, a converging lens array is provided between the EL element array and the image carrier (for example, see JP-A-63-103288 and JP-A-2004-58448 (FIG. 7)). For example, SLA (SELFOC lens array) available from Nippon Sheet Glass Co., Ltd. is used as an example of the conversing lens array (SELFOC is a registered trade mark of Nippon Sheet Glass Co., Ltd.).
FIG. 1 is a perspective view schematically illustrating a portion of an image printing apparatus using the converging lens array according to the related art. In the image printing apparatus, a converging lens array 40 is provided between a photosensitive drum 110 and a light-emitting panel 12 provided with the EL element array. Light emitted from the EL element array of the light-emitting panel 12 passes through a plurality of distributed index lenses of the converging lens array 40 to reach the photosensitive drum 110.
In general, the image printing apparatus is designed such that the ideal value, that is, the design value of an object distance Lo of the converging lens array to an object is equal to the ideal value, that is, the design value of an object distance L1 to an image. Therefore, when the converging lens array 40 is provided between the light-emitting panel 12 and the photosensitive drum 110, a distance between an incident point of light on the converging lens array 40 and the EL element array is generally equal to a distance between an emission point of light from the converging lens array 40 and the photoreceptor 110, serving as an image carrier.
However, since an air layer having the same thickness as the object distance Lo exists between the incident point of light on the converging lens array 40 and the EL element array, some of light components emitted from the EL elements are not incident on the converging lens array 40. That is, this structure has a problem in that the usage efficiency of light is deteriorated.